Scraper mechanism



" May 20,;1930. ASJ. cLAUsEN 1,759,251

SCRAPER MECHAISM Filed oct. 4, 1927 Patented May 20, 1930 PATENT OFFICE ANDREW J'. CLAUSEN,YOF SAN FRANCISCO, CALFORNIA SCRAPER MECI-IAN ISM Application 111ed October 4, 1927. Serial No. 223,868.

My invention relates to scraper mechanisms adapted to be used with machines for finishing concrete roads, and particularly with machines using reciprocating strike oifs or 5 screeds for working the concrete into place between forming tracks.

An object of my invention is to provide means to prevent waste of concrete over the tracks of a road finishing machine.

Another object is to prevent accumulation ofvmaterial on the tracks, thus disturbing the alinement of the machine and the level of the finished roadway.

A further obj ect is to provide means whereby undue stresses caused by large objects undesignedly introduced intothe aggregate and which might damage the mechanism, are automatically relieved.

My invention hasother objects and valuable features, some of whichv will be set forth in the following description of my invention which is illustrated in the drawings forming part of the specification. It is to be understood that I do not limit myself tothe showing made by the said description and drawings, as I may adopt varying forms of my invention within the scope of the claims.

Referring to the drawings:

Figure 1 is a front elevation of a road iinf' 30 ishing machine embodying my invention, a

portion of the screed being cut away to show the reciprocating mechanism.

Figure 2 isa detail of the scraper, drawn to an enlarged scale.

prises a scraper movably attached to the screed adjacent the track. The movement of the scraper renders it effective to move the road forming material away from the track,

40 but ineffective to move the material in the opposite direction. Means are provided for limiting the forces which can be applied to the scraper, to prevent damage due to unduly large or immovable objects accidentally introduced in the path of its movement.

A preferred form of my invention may be applied to a road finishing machine of well known type, comprising the tracks 6, which constitute a form between which the aggre- 5D gate 7 is worked to form the roadway. On

Broadly considered, my invention com-y to yemploy these movements separately or to gether as the nature of the work may require.

The screed rests on the tracks 6. The portions engaging the tracks are arched or inclinedupward slightly toward the center of the machine, and therefore as the screed is reciprocated it describes a slightly arcuate path. The road material or aggregate isdumped in front of the advancing machine, and the screed scrapes and works thev aggregate into al solidly compacted roadway, crowned in the center by reason of the arcuate motion of the screed.

Thev principal difliculty in operating the known device thus briefly described is its tendency to work the aggregate .over the tracks, thus wasting material and even blocking the operation of the machine until the track is cleared by the crew.V To prevent these wastes is the function of my invention.

Firmly bolted to the screed adjacent the track are the brackets 27 28, which carry the plate 29. Attached to the plate by the hinge 31 is the scraper 32, -which hangs in an approximately vertical position with its lower or scraping edge level withthe screed where it rests on the track.

An armf33, substantially perpendicular to the scraper and'riveted thereto, projects under the plate 29. Holes thru plate and arm allow free passage for the bolt 34. Between the head of the bolt and the arm is a washer' 36 on which the arm 33 rests, and abovey the plate a heavy compression spring 37 sur-v rounds the bolt and is surmounted by a washer 38 and a pair of jam nuts 39. Arm, bolt andy spring serve as ,a resilient stopV which tends to prevent the scraper from swinging outwardly, but permits it to do so in case it encounters any obj ect so unwieldly as to damage the equipment. Y l Y Y Y The inward swing of the scraper is unobstructed. For this reasonas it is moved toward the side of the roadway it is ineffective,

Ysince it may swing and drag over the aggregitudinally of thek screed, and means for maintaining the scraper in effective position during' one stroke ofthe reciprocatingrmo-Y tion and permitting its movement from said position 'during' the recovery stroke.

V2^.. In AQombinflfton With a road finishing machinehaving a screed, a scraper, means for imparting reciprocating motion thereto f longitudinally 4of the screed, and resilient means for maintaining the scraper in effect-ive position during one stroke of the reciprocating motion. i' Y Y y 3. In Vcombination with a road finishing machine having a screed, a hinged scraper,

means for imparting reciprocating motion thereto longitudinally of the screed, and means for maintaining the scraper in effective position during one Vstroke of the reciprof cat-ing motionv and permitting it to rswing from said position during the recover stroke.

4. In combination withl a road nishing machine having a screed, a scraper, means for imparting reciprocating motion'thereto longitudinally of the screed, resilient meansfor maintaining the scraper in effective position during one stroke of the reciprocating'motion and means permitting its movement from said position during its recovery stroke.

5. In combination with a road finishing machine working on a track, a scraper mounted Ven the machiner adjacent the track, means for imparting reciprocating motion to the scraper, and means for maintaining the scraper in effective position when moved inwardly vfrom the track and permitting its departure from said position when'moved outwardly.

. 6. In combination with a road finishing machine working .on a track, a scraper mounted on the machine adjacent the track,

4 means for imparting reciprocating motion to the scraper, resilient means for maintaining the scraper in effective position when moved inwardly from the track and means permitting free movement from said positio when moved'outwardly.

7. In a road finishing machine working on a Ytrackway.- and employing a reciprocating screed, a plate attachedto the screed in a .plane parallel to one of the tracks, a scraper adjacent said track hinged to the plate to permit it to Vswing freely, and aY spring controlled stop limitingits swing outward to.-V ward the track except when overstressed.

8. In a road finishing machine, a scraper plate mounted` for reciprocating movement Y across a field of operation, means for per-V mitting the plate to be thrust clear of material in its path of movement when Vmoving in one direction and for fixing the plate to move the material when it is moving in the other direction, and means for Vresiliently resisting movement Vof the plate relative to its mounting when moved in said other direc-V tion. i m a 9. In a road finishing machine, a scraper plate mounted for reciprocating movement across a field of operation, means for perf` mitting free movement of the plate when` stressed in one direction and means for re:

siliently resisting free movement when stressed in the opposite direction.

l0. In combination witha road machine having a reciprocating screed, Scrapers hinged to thescreed adjacent each end thereof and having their scraping surfinishirigVV faces disposed perpendicular tothe scraping edge of the screed, and stops for limiting `the outward movement of the Scrapers while permitting inward movement thereof.

In testimony whereof, I have hereunto set my hand.

ANDREW J. oLAUsEiv.

Y i., 13o 

